Not only women but also all the people desire to remain young. For this reason, there are various cosmetic means, such as esthetic treatments, basic skin care products, makeup products, special makeup, health foods, or cosmetic surgeries.
Objective evaluation of the youth, especially the youth of a face, in other words, objective evaluation of the gap between an actual age and an “impression age by appearance” is extremely important in evaluating the effect of various cosmetic means such as esthetic treatments and cosmetic materials.
However, for example, in order to evaluate the effect of esthetic treatments or cosmetic materials, when an impression age by appearance is used, the impression age by appearance may be influenced by the difference among evaluators or between sexes, so there is a problem in that the reproducibility of the evaluation may not be obtained.
The technique of estimating an age with good reproducibility is greatly needed in a wide variety of fields starting from the evaluation of the effect on the various cosmetic means such as esthetic treatments and cosmetic materials as described above to verification of age or marketing for liquor, cigarettes, and the like, security system for confirming the characteristic of the face for security, and the like.
In view of the circumstances, as an example of the technique, an age estimation method by using actual measurement value or sensory evaluation value of the size or the length of the eyes, the mouth, the nose, and the chin as a characteristic value has been known (Patent Literatures 1 and 2). In addition, an age estimation method that uses scores of the wrinkles or the flabbiness has been known (Patent Literature 3). In addition, a technique of estimating the age change based on the physical amounts (the size and the distance) of the portions or the component parts of the face (Patent Literature 4).
In recent years, according to the advance of image processing and statistical analysis processing in addition to the advance of imaging devices, there has been a dramatic advance in a system for monitoring and recognition by storing facial images on a computer quickly and accurately, recognizing an age group, a sex, and characteristics of the face, and estimating the person.
As examples of the technology, there have been known an age estimation system by using values from an image process such as an edge process or a binary process which is a characteristic amount contained in images (for example, Patent Literatures 5 and 6), a person attribution estimation technology by using characteristic values (the position, the shading, and the number of wrinkles) of characteristic points such as eyes, a nose, and a mouth (for example, Patent Literature 7), an age estimation technology for selecting a discriminator and a method for applying dimension compression to an image based on a perception age distance of a person as an evaluation standard (for example, Patent Literature 8). In addition, an age and sex determination technology by using similarity of characteristic information of a facial image (shading information per portion of the image, the size of the portion and the like) is disclosed (for example, Patent Literature 11).
Meanwhile, recently, a technology focusing on spatial frequencies, that is, a technology focusing on the change of the texture characteristics of an image by spatial cycles is developed. For example, a method of preparing a simulation image of skins presenting various textures according to the changes of spatial frequencies is disclosed (for example, Patent Literature 9).
The applicant of the invention discloses a technology of evaluating the effect on the “three dimensional effect of a face” that a makeup has, by performing spatial frequency pattern analysis at the time of the makeup by using the technology of using the spatial frequencies (for example, Patent Literature 10).